Like water through a hose, blood flows through your arteries, delivering oxygen and nutrients to your organs. Atherosclerosis occurs when your arteries become clogged with fatty deposits (known as plaque), causing them to lose their elasticity and narrow. This blocks or slows the smooth passage of blood.
Plaque is a sticky, yellow substance made up of fatty materials such as cholesterol, calcium, and waste products from your cells. Atherosclerosis is a slow, progressive condition that may begin as early as childhood. It can occur anywhere in the body but usually affects large and medium-sized arteries.
Atherosclerosis, heart disease and stroke
The causes of atherosclerosis are complicated and still not completely understood. Atherosclerosis is thought to start when the inner lining of the artery becomes damaged. The blood vessel wall reacts to this injury by depositing fatty substances, cholesterol, calcium and other substances on the inner lining of the artery. This plaque formation gradually narrows the blood vessels, making it harder for blood to flow. Plaque can also break apart and cause a blood clot to form on the broken surface or move through the bloodstream, and prevent smooth blood flow to nearby organs. The resulting blood clot can also travel to other parts of your body and block blood flow to other organs.
Atherosclerosis, heart disease and stroke
Atherosclerosis is related to coronary artery disease, stroke and other conditions. Depending on which artery is blocked, you may have:
Coronary artery disease (CAD). If arteries supplying blood to your heart become narrow or blocked, blood flow to the heart can slow down or stop. CAD can cause angina or heart attack. These heart conditions caused by atherosclerosis can be described as acute coronary syndromes.
Carotid artery disease. If arteries in your neck become narrow or blocked, blood flow to the brain can slow down or stop. A blood clot can also travel through the arteries to the brain and block vessels in the brain. This may cause you to have a stroke or mini-stroke (TIA).
Peripheral arterial disease (PAD). If arteries in your pelvis, legs or arms become narrow or blocked, you may develop peripheral arterial disease (PAD), leading to cramping muscular pain while walking or during exercise. It can be the first sign of atherosclerosis elsewhere in the body. PAD may also affect the arteries supplying blood to your head, kidneys or stomach, increasing the risk for a stroke and organ damage respectively. Learn more about PAD from the American Heart Association and Vascular Disease Foundation.
Aneurysm. Atherosclerosis can cause an aneurysm, which is a bulge in a weakened area of your artery wall. The bulge can burst and cause internal bleeding in the brain. It can be fatal when an aneurysm in the largest artery (aorta) bursts.
Risk factors for atherosclerosis include high blood pressure, high blood cholesterol, diabetes, obesity (increased BMI or waist circumference), , consuming a high fat diet, or a family history of heart disease. Find out more about how you can reduce your risk.
Sometimes atherosclerosis causes no symptoms until it is far enough advanced to block a large part of an important blood vessel. If the blockage occurs in an artery of the heart (coronary artery), it will cause angina (chest pain). As it progresses, atherosclerosis in the arteries of the heart may cause a heart attack or if it develops in the brain, it can cause a stroke.
Atherosclerosis can be diagnosed using:
Your doctor will treat your atherosclerosis with lifestyle changes, medications, surgery or other procedures.
You can lower your risk of atherosclerosis, heart disease and stroke by knowing and controlling your blood pressure, diabetes and blood cholesterol. It is also important to lead a healthy lifestyle by being smoke-free and physically active, eating a healthy diet that is lower in fat, especially saturated and trans fat, achieving and maintaining a healthy weight, limiting alcohol use and reducing your stress.
You may be prescribed a medication to reduce fats and cholesterol in your blood or medications to control your blood pressure. Sometimes antiplatelets or anticoagulants may be prescribed to reduce your risk of developing a blood clot. Learn more about medications.
Surgical and other procedures
Your doctor may suggest that you undergo certain procedures or surgery to treat your condition. They may include:
Percutaneous coronary intervention (PCI or angioplasty with stent)
Carotid endarterectomy (Surgery to remove plaque from the carotid artery)
Coronary artery bypass surgery
Last modified: August 2013
Last reviewed: August 2013